Steve Gottlieb
July 31st, 2013, 07:27 PM
8) NGC 1850 region
NGC 1836 (24"): bright LMC cluster, relatively large, high surface brightness, very elongated NW-SE, 1.2'x0.4'. The dominant portion of the cluster is on the NW end and appears bright, roundish, 25"-30" diameter with a few stars resolved just outside the glow. A 14th magnitude star is off the SE side and connects to a small knot containing a very tight string of 15th magnitude stars. Forms a striking pair with NGC 1839 2.5' E. HS 109 is 5.4' S and several other small clusters are in the field.
NGC 1839 (24"): very bright cluster forming a striking pair with NGC 1836 just 2.5' W. At 200x appears as a very high surface brightness irregular glo, ~30" diameter, mottled but not resolved. A group of six mag 13-14 stars is off the west side in two short N-S strings. Several fainter clusters are in the field including HS 117 5' SSE, HS 109 6' SSW and S-L 234 6' SE.
NGC 1847 (24"): very bright LMC blue globular, moderately large, irregular elongated shape, high surface brightness glow with a small fainter halo, ~0.6'x0.4'. At 200x, several mag 14.5-15.5 stars are resolved (a couple are fairly easy) within and at the edges of the central glow. NGC 1825 lies 15' WNW, NGC 1856 is 16' SE and NGC 1855/1858 are ~15' NE.
NGC 1850 (24"): at 350x in the 24" I was stunned by the view of this huge, extremely bright, blue globular cluster! The outer halo, which extends 5' in diameter, was resolved into dozens of faint stars arranged in irregular star chains that appear to stream out of the core. A single brighter mag 13 star is superimposed on the west side [30" W of center is the core of companion cluster N1850A]. The center is highly concentrated with an extremely bright 1' core that appears elongated, irregular and clumpy with a curved outline. A small, 20" diffuse glow is embedded at the north edge of the halo (open cluster S-L 260). NGC 1850 resides in a glorious LMC region that is packed with an unbelievable number of clusters and HII regions including NGC 1854 6' SE and NGC 1858, a huge cluster and nebulosity, ~10' SE.
18": After the Tarantula region (30 Doradus complex), NGC 1850 is the brightest star cluster in the LMC and at an estimated age of only 40-50 million years, this rich, globular-like cluster has no counterpart in the Milky Way! At 128x, the cluster appeared very bright (9th magnitude), large, round, ~3.5' diameter, well concentrated with an intensely bright 1' core. A brighter mag 13 star is superimposed on the western side of the halo. Several very faint stars are resolved in the very lively halo.
NGC 1850 lies in a very impressive region of the LMC (near the outskirts of the central bar) with 13 additional NGC clusters/nebulosity within 30' including NGC 1854 7' SE, NGC 1858 10' SE, NGC 1856 22' SSE and several others including NGC 1836, 1839, 1847, 1860, 1863, 1865. Unfortunately dawn was starting to break so I only was able to view the first group of objects mentioned above and I need to return to this field! See image at http://antwrp.gsfc.nasa.gov/apod/ap010712.html.
NGC 1854 (24"): I revisited this remarkable field after viewing NGC 1850 (located 6' NW) the previous night. At 200x this cluster appeared very bright, large, round, with a brilliant core. At 350x, it was resolved into numerous faint stars around the edges of the intense core. Up to a couple of dozen very faint stars popped in and out of visibility. The core is noticeably elongated N-S and is surrounded by a large, much fainter halo. There is a small clump of stars at the NW edge. NGC 1858, a large star cluster and nebulosity, lies 4' SE.
NGC 1855 (24"): see description for NGC 1854. According to John Herschel's descriptions, NGC 1854 refers to the core and 1855 refers to the halo of this large cluster.
NGC 1856 (18"): at 128x, this LMC rich cluster appeared bright, moderately large, 1.5' diameter. Well concentrated with a very bright 30" core similar to a globular cluster. Located 2' N of mag 9.4 HD 34144 and 23' SSE of NGC 1850.
NGC 1858 (24"): this would be a fascinating nebula and cluster (association LH 31) if it were isolated, but is even more striking situated at the southeast end of a wonderful chain with the bright cluster NGC 1854 and NGC 1850, which is one of the top showpieces in the LMC. At 346x about two dozen stars were superimposed over an elongated glow and many other stars are just outside the glow. At 200x with a UHC filter, the nebula is very bright overall with a 30" very high surface brightness patch at the north end. The nebula is brightest along the west and east border and weaker in the center. The elongation is towards a mag 12 star on the south side. NGC 1854 lies 4.5' NW.
18": third of three bright objects in a NW to SE string with NGC 1850 and NGC 1854/55. This is a large and very unusual cluster with nebulosity. There is a bright knot attached near the NW edge, ~15"-20" in diameter. This knot responds very well to a UHC filter at 76x (27 Panoptic). An obvious elongated patch of nebulous haze curves to the SE with several mag 13 stars involved with the glow and extended N-S. Overall, the size of the cluster/nebulosity extends to 3.5'x2'. Located 4.5' SE of NGC 1854.
NGC 1860 (24"): this LMC cluster was fairly faint, moderately large, possibly elongated slightly N-S, ~35"x30", very weak concentration. A mag 10 star lies 1.7' SW. Picked up after viewing NGC 1863 (5.5' ENE) and NGC 1865 (9.5' ESE). The amazing field containing NGC 1850 (brightest cluster in the LMC), NGC 1854 and 1858 is just to the SW.
NGC 1863 (24"): at 200x this LMC globular appeared very bright, moderately large, irregular outline, ~40" diameter, high surface brightness. A faint star or clump is at the NE edge. Forms a pair with NGC 1865, located 5' SE. The remarkable field containing NGC 1850 (brightest cluster in the LMC), NGC 1855 and 1858 lies 15' SW.
NGC 1865 (24"): at 200x this LMC cluster was fairly bright, fairly large, round, 1' diameter with a weak concentration and no resolution. It has a symmetrical appearance like a globular. Located 5' SE of the bright cluster NGC 1863.
HS 109 (24"): picked up while viewing NGC 1836 and 1839, a bright pair of clusters 6' N. At 200x appeared moderately bright, fairly small, irregular, 25"-30" diameter, a few very faint stars resolved.
HS 117 (24"): moderately bright, fairly small, roundish, 25"-30" diameter, involves a 14th magnitude star. Picked up while viewing NGC 1836 and 1839, a bright pair of clusters ~6' NW. S-L 234 lies 2.7' ESE and HS 109 is 4.4' WSW.
NGC 1836 (24"): bright LMC cluster, relatively large, high surface brightness, very elongated NW-SE, 1.2'x0.4'. The dominant portion of the cluster is on the NW end and appears bright, roundish, 25"-30" diameter with a few stars resolved just outside the glow. A 14th magnitude star is off the SE side and connects to a small knot containing a very tight string of 15th magnitude stars. Forms a striking pair with NGC 1839 2.5' E. HS 109 is 5.4' S and several other small clusters are in the field.
NGC 1839 (24"): very bright cluster forming a striking pair with NGC 1836 just 2.5' W. At 200x appears as a very high surface brightness irregular glo, ~30" diameter, mottled but not resolved. A group of six mag 13-14 stars is off the west side in two short N-S strings. Several fainter clusters are in the field including HS 117 5' SSE, HS 109 6' SSW and S-L 234 6' SE.
NGC 1847 (24"): very bright LMC blue globular, moderately large, irregular elongated shape, high surface brightness glow with a small fainter halo, ~0.6'x0.4'. At 200x, several mag 14.5-15.5 stars are resolved (a couple are fairly easy) within and at the edges of the central glow. NGC 1825 lies 15' WNW, NGC 1856 is 16' SE and NGC 1855/1858 are ~15' NE.
NGC 1850 (24"): at 350x in the 24" I was stunned by the view of this huge, extremely bright, blue globular cluster! The outer halo, which extends 5' in diameter, was resolved into dozens of faint stars arranged in irregular star chains that appear to stream out of the core. A single brighter mag 13 star is superimposed on the west side [30" W of center is the core of companion cluster N1850A]. The center is highly concentrated with an extremely bright 1' core that appears elongated, irregular and clumpy with a curved outline. A small, 20" diffuse glow is embedded at the north edge of the halo (open cluster S-L 260). NGC 1850 resides in a glorious LMC region that is packed with an unbelievable number of clusters and HII regions including NGC 1854 6' SE and NGC 1858, a huge cluster and nebulosity, ~10' SE.
18": After the Tarantula region (30 Doradus complex), NGC 1850 is the brightest star cluster in the LMC and at an estimated age of only 40-50 million years, this rich, globular-like cluster has no counterpart in the Milky Way! At 128x, the cluster appeared very bright (9th magnitude), large, round, ~3.5' diameter, well concentrated with an intensely bright 1' core. A brighter mag 13 star is superimposed on the western side of the halo. Several very faint stars are resolved in the very lively halo.
NGC 1850 lies in a very impressive region of the LMC (near the outskirts of the central bar) with 13 additional NGC clusters/nebulosity within 30' including NGC 1854 7' SE, NGC 1858 10' SE, NGC 1856 22' SSE and several others including NGC 1836, 1839, 1847, 1860, 1863, 1865. Unfortunately dawn was starting to break so I only was able to view the first group of objects mentioned above and I need to return to this field! See image at http://antwrp.gsfc.nasa.gov/apod/ap010712.html.
NGC 1854 (24"): I revisited this remarkable field after viewing NGC 1850 (located 6' NW) the previous night. At 200x this cluster appeared very bright, large, round, with a brilliant core. At 350x, it was resolved into numerous faint stars around the edges of the intense core. Up to a couple of dozen very faint stars popped in and out of visibility. The core is noticeably elongated N-S and is surrounded by a large, much fainter halo. There is a small clump of stars at the NW edge. NGC 1858, a large star cluster and nebulosity, lies 4' SE.
NGC 1855 (24"): see description for NGC 1854. According to John Herschel's descriptions, NGC 1854 refers to the core and 1855 refers to the halo of this large cluster.
NGC 1856 (18"): at 128x, this LMC rich cluster appeared bright, moderately large, 1.5' diameter. Well concentrated with a very bright 30" core similar to a globular cluster. Located 2' N of mag 9.4 HD 34144 and 23' SSE of NGC 1850.
NGC 1858 (24"): this would be a fascinating nebula and cluster (association LH 31) if it were isolated, but is even more striking situated at the southeast end of a wonderful chain with the bright cluster NGC 1854 and NGC 1850, which is one of the top showpieces in the LMC. At 346x about two dozen stars were superimposed over an elongated glow and many other stars are just outside the glow. At 200x with a UHC filter, the nebula is very bright overall with a 30" very high surface brightness patch at the north end. The nebula is brightest along the west and east border and weaker in the center. The elongation is towards a mag 12 star on the south side. NGC 1854 lies 4.5' NW.
18": third of three bright objects in a NW to SE string with NGC 1850 and NGC 1854/55. This is a large and very unusual cluster with nebulosity. There is a bright knot attached near the NW edge, ~15"-20" in diameter. This knot responds very well to a UHC filter at 76x (27 Panoptic). An obvious elongated patch of nebulous haze curves to the SE with several mag 13 stars involved with the glow and extended N-S. Overall, the size of the cluster/nebulosity extends to 3.5'x2'. Located 4.5' SE of NGC 1854.
NGC 1860 (24"): this LMC cluster was fairly faint, moderately large, possibly elongated slightly N-S, ~35"x30", very weak concentration. A mag 10 star lies 1.7' SW. Picked up after viewing NGC 1863 (5.5' ENE) and NGC 1865 (9.5' ESE). The amazing field containing NGC 1850 (brightest cluster in the LMC), NGC 1854 and 1858 is just to the SW.
NGC 1863 (24"): at 200x this LMC globular appeared very bright, moderately large, irregular outline, ~40" diameter, high surface brightness. A faint star or clump is at the NE edge. Forms a pair with NGC 1865, located 5' SE. The remarkable field containing NGC 1850 (brightest cluster in the LMC), NGC 1855 and 1858 lies 15' SW.
NGC 1865 (24"): at 200x this LMC cluster was fairly bright, fairly large, round, 1' diameter with a weak concentration and no resolution. It has a symmetrical appearance like a globular. Located 5' SE of the bright cluster NGC 1863.
HS 109 (24"): picked up while viewing NGC 1836 and 1839, a bright pair of clusters 6' N. At 200x appeared moderately bright, fairly small, irregular, 25"-30" diameter, a few very faint stars resolved.
HS 117 (24"): moderately bright, fairly small, roundish, 25"-30" diameter, involves a 14th magnitude star. Picked up while viewing NGC 1836 and 1839, a bright pair of clusters ~6' NW. S-L 234 lies 2.7' ESE and HS 109 is 4.4' WSW.